Tool · UV exposure timer
The exposure timer built for the workshop, hands busy.
Drag the dial to set the time, haptic and audio feedback (one click per minute), a progress ring visible from across the room, several simultaneous timers for successive passes. Available on the Web — and linked to your UV panel via Bluetooth control.
What the timer does
A countdown designed for the darkroom.
01 · Drag-to-set dial
Drag the dial to set the minutes without typing a number. Ergonomics for wet or gloved fingers — no keyboard required.
02 · Haptic & audio feedback
One click per elapsed minute. End of exposure signalled by a long vibration and a distinct sound — you hear it even with your back turned.
03 · Progress ring
An SVG arc visible from two metres shows the percentage of time elapsed. A glance is enough, without approaching the screen.
04 · Parallel timers
Run several countdowns at once — pass 1, pass 2, development bath. Each timer runs independently, with its own ring.
Availability
The timer is free on the Web and in the iOS app, with the same account (sign-up required). Only curve export as .acv requires Pro mode (€9.90/month, or 1 year included with a Luminograph).
Linked to your UV panel
Automatic LED on and off.
The timer alone counts the time — you turn the UV source on and off. To go further, Calibration Flow’s Bluetooth UV control drives the LED panel directly: automatic start and stop at the end of the countdown, with no manual intervention.
This synchronisation requires a compatible controller connected to your panel, plus the native iOS app or Chrome desktop (Web Bluetooth). It is not available on other mobile browsers.
The result: you place the negative, you start, you step away. The panel switches off on its own — zero over-exposure, zero handling in the darkroom under white light.
Documentation
Manual & resources
- Manual · Harmonic timer — Calibration Flow — advanced use, pass sequences, harmonic calibration
- Bluetooth UV control — automatic LED panel control
- Manual · Calibration Flow tools — histogram, loupe, Smart Analyzer, UV calculator
- UV exposure time calculator — estimate the time before launching the timer
A calmer workshop, a more precise exposure.
Timer, UV calculator, 21-step chart — free on the Web with sign-up. .acv curve export — Pro at €9.90/month or Luminograph 1 year.